1. Field of the Invention
This invention relates to liquid atomizers and more particularly it concerns a self contained battery powered atomizer which uses a vibrated orifice plate to produce and eject aerosolized particles from a liquid supply.
2. Description of the Related Art
Self contained battery powered liquid atomizing devices are well known and are described, for example, in U.S. Pat. Nos. 4,294,407; 4,300,546; 4,334,531; 4,479,609; 4,793,339, 4,877,989; 5,529,055 and 5,803,362. These known devices are generally expensive to manufacture and are impractical for use in household applications such as dispensing of fragrances, insecticides and the like, while retaining the precision necessary for such operations.
The present invention makes possible a reliable yet inexpensive and easily manufactured and assembled, battery powered liquid atomizing device having a conveniently replaceable liquid reservoir which can be positioned in the device with the precision necessary for proper supply of liquid to the atomizing mechanism.
According to one aspect of the invention there is provided in a liquid atomizer device, a hollow shell-like outer housing or top cover formed with an upper atomized liquid ejection opening and a generally horizontal integrally molded chassis or support inside the outer housing and which divides the interior of the top cover into upper and lower regions. The support is formed with a passageway which communicates between the upper and lower regions in the top cover. The support is also formed, on its upper and lower sides, respectively, with upwardly and a downwardly facing locating surfaces next to the passageway. The upwardly facing locating surface locates a vibratory orifice plate on the upper side of the support and the downwardly facing locating surface locates a replaceable liquid reservoir on the lower side of the support. The support is further formed with an upwardly facing camming surface which is located below the downwardly facing surface and this camming surface holds a liquid reservoir up against the downwardly facing locating surfaces for precise positioning of a liquid reservoir relative to an orifice plate mounted on said upwardly facing locating surface. Because the upwardly and downwardly facing locating surfaces are formed on the same support, the orifice plate, which locates on the upwardly facing surface, and the liquid reservoir, which locates on the downwardly facing surface, can be positioned precisely relative to each other, even when a replacement liquid reservoir is inserted into the dispenser. As a result, a wick, which extends out of the reservoir, delivers the liquid to the orifice plate without appreciably damping its vibrations. Thus, liquid is delivered to the orifice plate without any interference with vibration of the plate.
According to a second aspect of the invention, there is provided a liquid atomizer device which comprises a hollow shell-like outer housing or top cover formed with an upper atomized liquid ejection opening and a generally horizontal chassis or support which divides the interior of the top cover into upper and lower regions. The support is formed with a passageway communicating between the upper and lower regions; and it is also formed, on its upper and lower sides, respectively, with mounting formations for mounting an orifice plate in an upper region of the passageway and for removably mounting liquid reservoir in a lower region of the passageway. The support is also formed on its upper side with circuit mounting elements for mounting an electrical drive circuit which causes an orifice plate to vibrate. In addition, the support is formed on its lower side with battery mounting elements. This arrangement provides easy access for replacement of either or both the battery and the liquid reservoir without disturbing the vibratory orifice plate or the drive circuit.
According to a further aspect of the invention, there is provided a novel retainer assembly for a piezoelectric atomizing pump of the type which comprises an annular piezoelectric element having a center opening and an orifice plate fixed to the element and extending across its opening. This novel retainer assembly comprises a vertically extending generally cylindrical wall within which a piezoelectric atomizing pump assembly may fit. The tubular support is also formed with an inwardly extending shelf for supporting the piezoelectric pump assembly. A pump assembly retainer is also provided. This retainer has a laterally extending annular wall which rests on the upper end of the cylindrical wall above the shelf and is removably secured to the tubular support. A plurality of resilient retainer elements extend downwardly from an inner edge of the annular wall and inside the tubular support to press on and hold the piezoelectric pump assembly which rests on the shelf. This allows the piezoelectric pump assembly to be precisely positioned on the shelf; and yet, because of the resilient retainer elements, any variations in the size of the tubular support, the pump assembly retainer or the piezoelectric pump assembly are accommodated by the flexing of the resilient retainer elements.
In a still further aspect, the present invention provides an easily assemblable, self contained liquid atomizer assembly which comprises a hollow molded outer shell or top cover having support projections which extend inwardly from an inner surface thereof and retainer formations which are located below the support formations. The top cover is also formed with an upper atomized liquid ejection opening. There is also provided a unitary molded internal chassis or support having a flange-like surface which can be snapped into place inside the top cover to rest against the support projections inside the top cover. The internal support has a passage which is aligned with the ejection opening in the outer shell when the support is snapped into place. The upper side of the internal support is formed with upwardly facing support surfaces on which a printed circuit board may rest and on which a piezoelectric pump assembly, positioned over the passage, may rest. The upper side of the support is also provided with snap elements which permit the printed circuit board and the pump assembly to be snapped into and held in place on the upper side of the internal support. The lower side of the internal support is formed with releasable retainer elements for releasably holding a liquid reservoir under the passage and for releasably holding a battery adjacent to the reservoir. Finally, the internal support is formed with openings to accommodate wires which extend from a battery held under the support to a printed circuit board held above the support and which extend from the printed circuit board to the piezoelectric pump assembly held on the upper side of the support.